Biology subjects

Fukatsu, R.

Publications and source records attributed to Fukatsu, R..

3 recordsLinked to original sources

bioRxiv2021

State-Anxiety Modulates the Effect of Emotion Cues on Visual Temporal Sensitivity in Autism Spectrum Disorder

Atypical processing of stimulus inputs across a range of sensory modalities in autism spectrum disorders (ASD) are widely reported. Sensory processing is known to be influenced by bodily internal states such as physiological arousal and anxiety. Since a sizeable proportion of ASD individuals reportedly have co-morbid anxiety disorders that are linked with dysregulated arousal, we investigated if face-emotion arousal cues, influenced visual sensory sensitivity (indexed by temporal resolution) in an ASD group (n=20) compared to a matched group of typically-developed individuals (TD, n=21). We asked further if emotion-cued changes in visual sensitivity associated with individual differences in state- and trait-anxiety. Participants reported the laterality of the second of two consecutive Gaussian-blob flashes in a visual temporal order judgment task (v-TOJ), demanding higher-level visual processing. The key manipulation was presenting a task-irrelevant face emotion cue briefly at unexpected time points preceding the task-relevant flashes. Disgust vs Neutral emotion signals enhanced the visual temporal resolution in ASD individuals. Furthermore, individual state-anxiety scores correlated with the emotion-cued change of temporal resolution (Disgust vs Neutral) in the ASD group. Both these effects were absent in the TD group. The results show that individual state-anxiety levels significantly modulate the effect of emotions on visual temporal sensitivity in ASD individuals, which was absent in our TD sample. The findings support a nuanced approach to understand the disparate sensory features in ASD individuals, by factoring in the interplay of the individual reactivity to environmental affective information and the severity of anxiety.

neuroscience↗

bioRxiv2020

Temporal resolution relates to sensory hyperreactivity independently of stimulus detection sensitivity in individuals with autism spectrum disorder

BackgroundResearchers have been focused on perceptual characteristics of autism spectrum disorder (ASD) in terms of sensory hyperreactivity. Previously, we demonstrated that temporal resolution, which is the accuracy in differentiating the order of two successive vibrotactile stimuli, is associated with the severity of sensory hyperreactivity (Ide et al. 2019). Herein, we examined whether an increase in the perceptual intensity of a tactile stimulus, despite its short duration, is derived from high temporal resolution and a high frequency of sensory temporal summation. MethodSixteen participants with ASD and fifteen typically developing (TD) participants performed two psychophysical experimental tasks, and we evaluated the detectable duration of vibrotactile stimuli with the same amplitude and temporal resolution. Sensory hyperreactivity was estimated using a self-reported questionnaire. ResultsThere was no relationship between temporal resolution and the duration of detectable stimuli in either group. However, the ASD group showed more severe sensory hyperreactivity in daily life than the TD group did, and ASD participants with severe sensory hyperreactivity tended to have high temporal resolution but not high sensitivity for detectable duration. ConclusionContrary to our hypothesis, there might be different processing between temporal resolution and sensitivity for stimulus detection. Sensory reactivity in daily life would not be based on sensitivity for stimulus detection measured in an experimental task, and we suggest that atypical temporal processing would affect sensory reactivity in ASD. Keywords (within 6 keywords): Temporal resolution, Temporal summation, Autism spectrum disorder, Hyperreactivity, Gap detection

neuroscience↗

bioRxiv2020

Decreased utilization of allocentric coordinates during reaching movement in individuals with autism spectrum disorder

Despite numerous reports of abnormalities in limb motor controls in spatial orientation in individuals with autism spectrum disorder (ASD), the underlying mechanisms have not been elucidated. We studied the influence of allocentric coordinates on ongoing reaching movements, which has been reported to strongly affect the reaching movements of typically developing (TD) individuals. ASD and TD participants observed a target presented randomly on one of the four corners of a frame on a screen. After it disappeared, another frame was presented slightly shifted leftward/rightward. The participants touched the memorized position of the target relatively congruent with a reference frame (allocentric condition) or ignoring it (egocentric condition). Results suggested that touch positions were less affected by shift directions of reference frame in the allocentric condition in ASD participants, so that they tended to reach in egocentric manner. Our findings demonstrate that decreased utilization of visual landmarks in ongoing movement may underlie motor disabilities in autism.

neuroscience↗